Investigators say many fireworks that are illegal in Washington state, are sold on reservations.

"Anything that is legal under federal regulation, you can buy on an Indian reservation, but you cannot buy illegal flash powder devices. Those are not legal anywhere," Dausch of the Puyallup Tribal Police said.

One of the most popular illegal fireworks is the lightsaber, that shoots M-80s.

"A child had their hand taken off at the Muckleshoot Reservation last year with one of these," Phillips said.

Sometimes they even find regular folks, trying to light large professional fireworks off in their backyard.

"These could be deadly and we had a fatality in the Tri-Cities last year with this very with this very type of shell," Phillips said.

If you are caught buying or selling illegal fireworks, the feds say they will prosecute.

"It certainly doesn't make sense in my mind to ruin your July 4th season by becoming a felon," Phillips said.